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The shipment must be registered before the label is available. If registering a shipment (e.g. through the Parcel Booking API ) and fetching label is done in one action we recommend you verify a successful respons from the registration before you make a request to the label API. It's recommended to have at least a 2 second latency if using the booking API (we do not guaranty this will always be enough), and if If registrering the parcel is done through file or other formats we recommend a longer latency.
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